I’ve been noticing this for the past few weeks. If you’re a Herald and you have Upkeeps active from Facets, then enter the water, and exit the water. Next time you try to activate your Facet, it gets deactivated within 1-2 seconds by itself, and will continue to be deactivated whenever you try to activate it.
Seems to be some sort of Enter-Water bug where when you enter the water, it deactivates all Herald skills since Herald isn’t used underwater. But then when you come out of the water, and Herald is active again, it still remembers the water, and keeps deactivating your Facets within 1-2 seconds of turning them on.
Switching to another Legend and then switching back seems to reset Herald Upkeeps and allows Facets to stay on again.